refacto: Remake the interface so it is more 'vintage' looking + Adding a full calendar page

locales/en/common.json

@@ -10,7 +10,8 @@
     "aboutHistory": "History of the calendar",
     "aboutLeapYears": "Sextile years",
     "aboutComplementaryDays": "The complementary days",
-    "language": "Language"
+    "language": "Language",
+    "calendar": "Full calendar"
   },
   "home": {
     "todayHeading": "Today is",
@@ -44,5 +45,30 @@
     "text": "Dates computed with the perpetual arithmetic rule proposed by Gilbert Romme (19 Floréal, Year III / 8 May 1795).",
     "sourceNote": "Historical content adapted from the \"French Republican calendar\" reference article."
   },
-  "loading": "Loading…"
+  "loading": "Loading…",
+  "calendar": {
+    "title": "Calendar of the French Republic",
+    "subtitle": "The twelve months, the three décades and the days of the year",
+    "seasons": {
+      "autumn": "Autumn",
+      "winter": "Winter",
+      "spring": "Spring",
+      "summer": "Summer"
+    },
+    "decades": [
+      "1st décade",
+      "2nd décade",
+      "3rd décade"
+    ],
+    "dayColumn": "Days",
+    "explanationTitle": "Explanation",
+    "explanation": [
+      "The Republican year begins at the autumnal equinox. It has twelve months of thirty days, split into three décades of ten days, plus five complementary days, or six in sextile years.",
+      "Each day is named after a plant, an animal, a mineral or a farming tool: the fifth day of each décade honours an animal, the tenth a tool, and in Nivôse the days honour minerals. The day names are given in French, as in the original.",
+      "Tap a month name to see its engraving and its origin. The day shown on the home page is highlighted."
+    ],
+    "feastsTitle": "Complementary days",
+    "sextileOnly": "sextile years only",
+    "close": "Close"
+  }
 }